What Is and What Should Never Be
by poynter94
Summary: Tom Hiddleston/OC Multi-chapter fic to fill this prompt: Tom falls for his fiancé's little sister when she comes to visit. Cat has never told Tom much about her life before knowing him, so he doesn't know anything about his future sister-in-law prior to meeting her.
1. Prologue

**Prologue**

"Are you sure this is okay with you?" she asked for what seemed to be the hundreth time and he chuckled

"Yes, Cat, it is perfectly fine with me. I told you I wanted to meet your family, you're the one who never invites them over."

"My family is very loud and complicated Tom. But I promise you, if Steph turns into a burden I'll pack her bags and send her home right away."

They had been cleaning his flat for quite a while. It was late in the afternoon and if he were to be completely honest, he felt rather nervous about meeting his sister-in-law. He had only seen Catelyn's family through a computer screen, even though they had been engaged for six months and together for over two years. He asked for her mother's permission to marry her over Skype and had only seen her younger sister in pictures posted on Facebook. The two were complete opposites, Catelyn had light brown short hair and small hazel eyes. She was tall and lean, her skin was a light shade of caramel and she could pass for a runway model easily. Even though she worked as a nurse in one of the biggest hospitals in London. From what he could tell, Stephanie was a brunette, she had big expressive brown eyes, he hair was long and stopped at her waist, and her skin was a shade of tan that seemed to make her glow. He didn't know much about her, Cat didn't like talking about her family, what he did know is that they were half sisters and that the girl had been through some rough things. They also had an older sister, Jenna, who was married and lived somewhere in Oregon.

Stephanie's visit didn't really bother him much. He didn't have time to be bothered by it because his new movie was going to be released in a week, meaning that he probably wouldn't be home long. She was to stay over for a month or so, for reasons Catelyn avoided explaining. He wondered if he could convince Emma to show her around the town, he knew Cat wouldn't have the time or patience to play tourist guide for too long. How old was the girl anyways? He probably should have paid more attention to what his fiancé told him about her.

The premiere of Thor was a day away when she finally arrived in London. Stephanie grabbed her luggage looking around the airport completely mesmerized. She remembered when her sister moved to the city four years ago, she felt so jealous that it wasn't her moving to the other side of the world. Around that time all she ever wanted was to go to college in London and enjoy the European lifestyle. She even researched places to live, to eat and even made friends with people who would possibly live in 'her' neighborhood online. She smiled a little remembering how naive she had been as a teenager. Steph sat down at the Starbucks where she would wait for her sister. Cat was to pick her up and drive both of them to the flat she shared with her fiancé. She had seen a couple of pictures of the man, but couldn't really remember his face clearly as she was too busy with her own problems. Before she knew it, tears started to feel her eyes. Breathing deeply, she sat up and connected her iPad to the internet.

"Hello, little brat." she felt a hand on her shoulder

"Cat!" turning around, she hugged her sister and smiled almost automatically

"You really do miss me, don't you?"

"You know I do. Even though you betrayed me and decided to move to my favorite place in the world." she feigned annoyance

"Well, if you think about it, me moving here gave you the opportunity to visit your favorite city."

"Yeah, right." she looked around them "Wasn't your boo supposed to come with you?"

"He had a meeting or something. Wanna go home?" she grabbed one of her sister's bags

"Let's go!"

They drove for quite a while before reaching the flat. Throughout the drive, Stephanie could hear her sister laugh a little when she stared out of the window in awe. She didn't mind. They went up the stairs with the luggage and Cat showed her to her room. The flat was extremely clean, it had white furniture with some darker accents and it was rather large. It pleased her a lot, but somehow she couldn't bring herself to picture her older sister living there. It just wasn't her. The room she was to stay in was the closest to the bathroom, it had a queen sized bed with white bedding and a big window with an awesome view.

"So, now that you know how the whole flat is setup," Cat said as she finished giving her a tour of the flat "I'm going to get ready to go to work. I've got the graveyard shift today."

"Okay. Thank you so much for letting me stay here, Cat. I don't know what I would've done without your help."

"Don't mention it, sis."

She sat on the couch for a few minutes staring into space after her sister left. She didn't really know what to do. Watching TV didn't sound so exciting, she wanted to go places and see things. If only she even knew how to get anywhere. Her stomach growled and she laughed, deciding to go into the kitchen and prepare something that she could eat. Grabbing her iPod, she turned up her music and got to work. Jani Lane's voice set the rythm of the dance she was trying to perform. Steph knew she was the worst dancer in the whole world, but she didn't care. Shaking her hips, she threw the shrimp on the pan and started to mix it with the sauce she had made. 'Maybe I should add some hot sauce to this' she thought and turned to the food cabinet, but was forced to stop right after turning. A tall man was staring at her with his mouth slightly open. She felt her eyes grow bigger, and her cheeks burn. How long had he been there? Who the hell was this guy anyways?


	2. One

The meetings and interviews went on and on for the whole day. As much as he was happy to be receiving so much praise and congratulations for his work, Tom had to admit that it was all somewhat stressful. He wanted to go home, soak in his bathtub, drink a glass of fine wine and relax for a little while. But then he remembered, the premiere of his biggest movie to the date was in less than twenty four hour, relaxing was the last thing on his agenda and would remain that way for a long while. He sighed, those were the perks of having his work recognized. Though it would drive him to exhaustion, he couldn't complain. He had worked too hard to get this far and give up. As the cab drove through the unusually quiet streets of London, he realized how hungry he had been for the majority of the day. Eating properly was a hard task to accomplish, but hopefully he would be able to enjoy a nice homecooked meal upon arriving at home. He took a few extra bills out of his wallet and paid the driver, walking up the stairs towards his flat. Opening the front door he realized that except for the bathroom and kitchen, all of the rooms in the flat were almost pitch black.

"Cat?" he called out her name to no response

The bathroom was empty, she must have been in the kitchen. Tom walked towards the bright white room and encountered something that made him stop dead in his tracks. A strange female body moved from side to side in front of the stove, her long dark hair fell across her back as her hips swayed in what he assumed was the rythm of whatever song she listened through her bright pink earbuds. If he payed close attention, he could make out bits and pieces of the melody. Though it made him feel like a creep, he couldn't help but just standint here and staring at her. Who was this woman after all? As she turned to grab something inside one of the cabinets, she finally realized that there was someone else in the room. Tom opened and closed his mouth several times, not being able to say anything coherent. He saw her eyes grow bigger and bigger, and a few minutes after staring back and forth at each other she let out a high pitched scream that made both of them jump.

"Who the hell are you?" she growled, moving one of her hands closer to the knife set that was on the counter

"I am Tom. May I ask who are you? And why are you in my house?" he tried his best not to sound too rude, but she had yelled at him so he felt he had the right to be as rude as it would please him

"Oh my God. Tom! Right. You're Cat's fiancé. I am so embarassed and sorry. I completely forgot you lived here." she said faster than he thought was possible for a human being to do, he could barely understand a word that came out of her mouth "I am Stephanie. Cat's sister. I believe she told you I would be staying here for a while?"

"Oh, yes. Of course." but aren't you supposed to be like fifteen? "I'm sorry I startled you, I had so many meetings today and I completely forgot that it was the day of your arrival. You're a lot different from what I had imagined." damn you and your big mouth, Hiddleston

"Well, I was trying to cook some dinner. If you're hungry you can join me."

"I would love to. I have always wanted to meet your family, it will be awesome to bond with my new little sister." he smiled "I have to shower first, do you mind?"

"Not at all, dinner won't be ready for a while."

"Great, I'll see you in five or ten, then." he turned towards the hall where the bedrooms were and Stephanie turned back to her cooking

For some unknown reason, something about this guy had bothered her. Though he looked friendly, polite and…really handsome, she had the feeling she couldn't really trust him. Maybe she was being paranoid. God knows she had plenty of reasons to be. And what was that talk of 'bonding with his new little sister'? What kind of a loser went around saying this bs? Maybe English men were different.

Minutes later, Tom and Stephanie sat awkwardly across from each other on the table. They had tried to start up a conversation, but it never went far. Though he was curious about his soon-to-be new family, he felt that pushing the girl into a conversation wasn't ideal. She acted and talked in a rather defensive way, which made him wonder if something had happened in the past to make her behave that way. Though she didn't consider herself the best cook in the world, she could easily get by. On that specific night, she had made grilled chicken breast, rice and vegetables. Nothing too fancy, but it was surely better than what her sister was capable of cooking. She smiled a little, remembering the one time Cat had tried to bake some beans and almost set the entire neighborhood on fire. The man forced himself not to smile upon seeing the way her face seemed to glow with happiness. After dinner was ready, they cleared up the table and washed the dishes.

"I have a sister, Emma, she is probably almost your age. She would be glad to show you around London. That is if you wanted her to." he said as they were sitting in the living room

"That would be great. I really want to explore the city, I have wanted to come here for a long while." she smiled politely

"Oh, did you?"

"Yes, I wanted to go to college here. I mean, university."

"Cat had never told me about this. Did you have a specific university in mind?" she smiled shyly. It had been such a long time since anyone had showed any interest in whatever she had to say.

"Well, Cambridge would have been ideal, but I'm not that smart. So I settled for Westminster." he disagreed on her not being smart, if she was anything like her sister she was pretty darn smart

"And what made you give up on that idea?" he saw a flicker of shadow cross her face and she became instantly pale

"Things didn't go as I had planned them to." her voice sounded sad and pained

"Well, someday maybe eh? Who knows what the future holds in store for us?" Tom decided to change the subject, seeing as she was uncomfortable with that talk. They talked for an hour or so, discovering more about each other and their respective families. Stephanie realized that having Tom as a 'brother' wouldn't be as bad as she had initially thought. He was not only nice and polite, but also smart and extremely funny.

The doorbell woke her up the next morning. It took a minute or two to adjust her eyes to the light and her body to the new room. A few minutes later, she saw her sister walk into the room wearing her comfy sheep printed pajamas and smiling weakly. She looked exhausted.

"Steph, I'm glad you're awake. Emma is here." she sat on the edge of the bed

"Emma?"

"Yeah, Tom's sister. I thought you two were supposed to hang out today or something."

"Right! What time is it?"

"Just past ten."

"Okay, I'll take a quick shower and I'll be ready in fifteen." her sister eyed her funny and Stephanie knew something was wrong "Is everything okay, Cat?"

"Yes. Kinda. I don't know."

"Can I help?"

"As a matter of fact, you can."

"Just tell me what it is, you know I hate the suspense."

"Well, I thought they would let me out of work tonight, but the girl who was supposed to take my shift is sick so I have to take the graveyard shift again." she bit her lower lip and frowned slightly

"I can't stand blood. So I don't really know how I would be able to help you?"

"Well, tonight is the London premiere of Thor. I was supposed to accompany Tom, so I thought that maybe you-"

"Would want to go with him?" Stephanie's voice was louder than she had expected it to be

"It's just a formality, Steph. He hates gong to these things alone, and Emma has a date with her boyfriend tonight."

"Is he okay with this?"

"Of course! I wouldn't be asking you if I didn't know he would agree to doing this."

"I have nothing I could possibly wear to this kind of event, Cat."

"You could borrow something of mine?"

"You're a lot taller than me." she rolled her eyes

"Since you and Emma are going out, you can buy a dress for youself. How does that sound?"

"Alright."

"I'll ask her to take you to a beauty salon as well. Take care of that ridiculously long hair of yours."

"What's wrong with my hair?" she inquired slightly offended

"Nothing. But it sure ain't ready for a movie premiere. Perhaps you will find yourself a cute guy there, huh?"

"Whatever."

Emma had turned out to be a really nice girl. Stephanie almost felt bad for thinking hanging out with the blonde would have been a pain in the ass. She had introduced the new girl to some of her friends, they had shopped together, gossiped, gone to the salon and had a really fun day. By the time her and Emma got to the flat, it was already almost six o'clock. She had less than two hours to get ready before the driver would come for her and Hiddleston. Good thing her hair was already done and she knew her makeup well. As they opened the door, they heard a bedroom door being slammed loudly and saw the man, whose face was slightly reddened, walk into the living room. He smiled apologetically at them as they walked towards the guest room.

"Well, Steph. It was lovely meeting you. Don't forget that we are going to a pub tomorrow alright? Let's make good use of your age, since you can't drink yet in America." they laughed "And don't you worry about this premiere. I've gone to these things with Tom and they're usually a lot of fun. Great opportunity to meet new people. I got to go now. I'll call you tomorrow."

"Awesome. I loved meeting you too, Emma. It is so good to have someone to spend time with." as she closed the door, Stephanie tried hard not to feel nervous about going to the event. There would be so many celebrities there, as well as other important people. What if she tripped and fell? Did she have to stand in front of the photographers for the pictures? She sure hoped she wouldn't have to.

As she came out of the shower, she eyed her dress with doubtful eyes. She didn't want something so…sparkly. But Emma assured her that the dress was absolutely gorgeous and it fit her frame like a glove. Since she had no experience whatsoever on the matter, she decided to trust her opinion. Stephanie heard soft knocks on the door and her sister came into the room as she was zipping up the gown.

"Wow. You look fantastic!" Cat's smile was big and bright "I am so sure you're going to walk out of this party with a million men following you home."

"Don't be stupid. How does my hair look?"

"Amazing. You look like an amazon princess or something."

"If you say so."

"I just came to wish you an awesome time, and thank you once again for doing this. It means a lot to me knowing that I can count on you." they hugged

"I'm the one who should be thanking you Cat."

"Well, I better let you get going. I need to be at the hospital soon." she straightened up and pulled the top of her scrubs down

Doing her makeup didn't take too long. Stephanie didn't want to do too much and end up making a fool of herself in front of all of those people, so she stuck to the basics. Lining her eyes, putting a few coats of mascara and wearing a bold red lipstick. She put on her jewelry, grabbed her purse and thin coat, and tried not to trip on the exaggerately high heels Emma had insisted she buy earlier. She walked into the living room, where Tom was standing using his phone and cleared her throat. As he turned towards her, she felt overwhelmed by the gorgeous body in front of her eyes. His suit fit him perfectly, she could smell the strong, but not annoyingly strong, cologne he wore and he smiled at her offering his arm for her to take.


End file.
